An Experimental Might adventure set in Ptolus for characters of 6th or 7th level.

From the back of the book:

The Dungeon below Ptolus is sometimes called Ghul’s Labyrinth. Carved out of the earth by slaves and spells to house that evil lord’s armies and dark laboratories, this is a place where the wise tread carefully, if at all. And when adventurers run afoul of the threats hiding in these deeps, it takes an even greater band of delvers to find and rescue them. Particularly when mysterious dark tidings are afoot. . . .

Dark Tidings is a short dungeon adventure for characters of 6th or 7th level. It is set within Ptolus, Monte Cook's City by the Spire, but it’s suitable for any fantasy setting. It utilizes the feat rules, magical disciplines, and spell progression system from The Book of Experimental Might and The Book of Experimental Might II — now available in print as The Collected Book of Experimental Might — but you can run the adventure with the standard game rules as well.

Does your party dare to risk the dangers of the realms below to rescue fellow delvers in terrible trouble?